This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The recently discovered Sulf2 enzyme acts to modify heparan sulfate (HS) associated with cell surface and extracellular matrix proteoglycans. This remodeling affects cellular recognition of growth factor families including transforming growth factors, vascular endothelial growth factors, and fibroblast growth factors. Detailed structural information on the HS domain context required for Sulf2 activity is lacking due to analytical challenges. Such information is essential to understanding the functional roles of Sulf2 enzymes as a function of tissue location and temporal changes in the growth environment (development and disease).